Many persons suffer from various allergies, several of which are caused by ingesting foods containing allergens, which are usually proteins. Although the biochemistry of allergic reactions is not precisely understood, it is believed that proteinaceous allergens cause, upon ingestion or other contact with the human body, a specific reagin to be formed in the blood. The ability to produce reagins, chemically identified as IgE, in response to a given allergen is thought to be an inherited characteristic that differentiates an allergic person from a non-allergic person. The specificity of the allergen-reagin reaction is similar to the antigen-antibody reaction.
It has been estimated that ˜8% of children and 2% of adults have allergic reactions to food (Weangsripanaval et al., Journal of Nutrition: 2005, 1738-1744). Many common foods contain various allergens, and food allergy is common in both adults and children. Foods which are generally regarded as being particularly allergenic include chocolate, nuts, milk and milk byproducts, wheat, eggs, corn, pork, soybeans, tomatoes, oranges, crustaceans, rice, seafood, fish spices, condiments, wine, and other products of fermentation. Symptoms of food allergy range from mild to severe, and can include allergic skin eruptions, respiratory tract allergy (allergic rhinitis and asthma), gastrointestinal reactions, shock-like reactions, vascular collapse, and allergic anaphylaxis.
Peanuts are a very frequently consumed and popular food product. However, allergists have long-recognized that peanuts contain allergens. In fact, the peanut allergens are among the most severe common allergens, and have been referred to as “super allergens” because they account for at least 70% of severe anaphylactic reactions. Many studies have been done to characterize the special proteins responsible for peanut allergies. At least seven peanut allergens, belonging to three super protein families (Mills et al., Trends in Food Science & Technology 14: 145-46, 2003), have presently been identified and are classified as Ara h1 to Ara h8. Ara h2, Ara h6, and Ara h7 are 2S albumins with molecular weights between 3-9,000 Dalton; Ara h1, a 7S globulin, with a molecular weight between 50-70,000 Dalton; and Ara h3 and Ara h4, 7S globulins, with molecular weights between 30-40,000 Dalton. The common feature of these allergens is that they show unusually high stability to denaturation and proteolysis, a property that may contribute to their high allergenicity. The two major peanut allergens are seed storage proteins known as Ara h1, a member of the vicilin family, and Ara h2, a conglutin-homologue protein. These two allergens are recognized by serum IgE from >90% of peanut allergic patients (Maleki et al., Journal of Immunology: 2000, 164, 5844-5849).
Although peanuts are most often consumed raw, blanched (boiled for a short period of time), or roasted, or in the form of peanut butter, peanut milk, or peanut flour, and may thus be easily avoided by sensitive individuals, the myriad of hidden ways in which peanuts are used make it difficult to avoid all contact. For example, peanut oil, peanut butter, and peanut flour are very frequently used as ingredients in popular food products such as candy, ethnic foods, hydrogenated oils, margarine, vegetable burgers, spaghetti sauce, and chili. In addition, food products that normally do not contain peanuts or peanut products are frequently cross-contaminated with peanuts because the same machinery is often used to prepare several different food products. Contamination may also be picked up from storage bins.
The food industry has voluntarily adopted stringent regulations for the clean-up and labeling of peanut allergen-containing foods. Significant efforts and costs are expended each year in the recall of foods suspected to contain traces of peanut allergens. Accordingly, there exists a great need for a hypoallergenic peanut, both to improve food safety and to permit allergic individuals to enjoy this common and nutritious food. Accordingly, there is a need for a hypoallergenic food containing peanuts or peanut products, particularly one which has the taste and aroma of fresh peanuts.
Advantageously, the inventors have discovered that direct treatment of peanuts or peanut derivatives with a solution containing at least one endopeptidase in the manner described below can either substantially reduce (i.e., greater than about 30%) or completely eliminate allergenic activity, as indicated by immunoassays.